Tripod clamp



Inventor 60rgemz'tchell.

G- A. MITCHELL TRIPOD CLAMP Filed July '7, 195o Nov. 3, 1931.

l I ...l

mi L Ww.

A vPatented.Nov'.3,:1931

. ytrhis invention reime genefiiyftotripig,"

and to clamps fortelescoping tripod legsand like devices.

' It isa generali objectof the present inven-l tion' tof provide a telescoping tripodilegcon-- structiony andv a Vclamping device therefor which are simple in construction,inexpensive, and conveniently and quicklyfadl]ustable.,

In accordancewith" the presentinvention;

y,each tripod leg is formed :of an uppersec'tion i icomprising spaced `si despivote'd at,their upper ends toV the tripod head,`:and1 connected at their lowerendsby an encircling ferrule,y

and a'lower vsection comprising `a' single-'leg ,confined and longitudinally-slidable between :the twoV Sides' of 'chelirrer sectinfsdaisgtqtel# escope theiewith. 'upper Y leg-section asysembly iSCylindi-i al in manually rotatable ring within Qwhichil'afre camming elements 'adapted by virt'uej of rota'- tionof the ring rto exert radial-pressure inward lonthe upper leg sections so as to' clamp I 2-2-'of Fig.

o 3 isa transvers'esection talenon line n the operating ring" l Y' Fig. is afsectio:

' ing the device in released them tightly in assembly with the lowerleg section. This construction resultsina 'simpleclamping device that is easily and 'quickly 'op-v takingidown the tripod.,r

. The invention will heisetreff unaereasail from the following detailed description yof a Y present preferred embodiment thereof, refer-y ence for thispurposebeing had tothe accom? Perrine drawings, i115 .Whihfr` Y "Figa `1 isa side'elevation ofv vided with my improvements; "Fig12 is a viewjtalrenas 3-'-3 of Fig. 2';` l I Y Fig. 4.- is a transverse 'section ftaken Aonline 'yofFirQZ'--r f L t Fig. 5 a centrallongitu y inal section of ,'Fig. 'I a sectionsimilarl toriFigfrbut showing t-,hefde'vice'A in'V released position;l *Fig Sisay View simi lo Firjbutzshow;

. external frm; .widk surrounding thecylindrical vassembly is a gly conducive to inl,y

indicated line i its es@ tf.

irniron CLAMP .'Fig. 9 is a'perspective view ofv drical'clamping member; and v ig.' 10 is a perspective View showingthe upper endy ofthe lower tripodileg section. l

)In the drawings, the'numeral 10 designates generally a tripod having a rotatableheadfll supportingan instrument table 12, andfhaving lugs 13 to which the'upper ends ofthe spaced sides 14a of the upper leg sections 14 are'pivoted, as' indicated at 15. The.r two 60- the Cyan! uppe'leg'rsecton VSides 1465 Oeach leg'l are providedtwith curved outer surfaces' suchy that'the zupper leg section assembly is cylinf,

. dricalin' external form, and the two sides' 14a` of each leg y `'re connected at theirlowerends 65" v by'jan, V.encircling ferrule 16. TheV vinner op-y posed fac'es 17 of sides 14a are preferably formed grooves -18 within which are slidablytaken tongues 19 formedon the' op- ,A posite faces 20'of the lower leg'section 2L 70 The leg sections are so fitte'dtogether that the lower leg section normally slides smoothly and easilyV between the upper( leg sections, but the litis preferably not so loose that fthe lower lleg section will slide downwardlybe- 75 tween the upperv leg 'sections of its own weight when the' clampingdevice is released. Itis to be understood, however, that the cross sec'- tionalform of the leg sections here shown is 1; but one illustrative form, and thatany other 80 form may be substituted, if desired.

l Inlthe preferred form, he upper end ofy thelower leg section 20 is cut with a slot y22 parallelto itsfaces 20, 'and taken within this l slot is ythe middle or `crosspart 24lof acon- 85 tractible cylindrical, clamping element 2,5, each curved side26 offwhich'enc'ircles one of the'sidesrv 14o of the upper leg' section 14.

A pin'27 'fastensthefcross part 240i thel clamping Vmembers 25 to the upper end of the 90 lower leg section 21. This clamping element l' is preferably of resilient material and of the form illustrated, though it may beembodiedy in many` other forms within the broad scope of the invention,y as will be readilyapparent 95 to those; skilled 'in the art.- In the form-illus trated,f however, the clamping element is of e relatively thin.. resilient material, as spring brass. It isto ybe noted that the clam'pingf element may be y'considered asa 'cylindrical'100 f the sides of the member,'asrclearlyfshowm in the drawings.

i 'Y v member Vlongitudinally split.V toa'be- 'con-v tractible and expansible, the crosspart 24 serving simply as a connection with the lower leg section20, and being here shown simply as forming a connecting part between Vthe two curved sides 26 of the member'.

Upper and lower cams SO are pressed outwardly in the ywall of each sid'e126 of. the clamping member, the cams here shown tapering down from the side edges 26er around Carried around thel contractiblel clampingl member 25 is a relatively rotatable ring 34 having knurled raised portionsY 35' for' con venience, in'N gripping by the hand for operoperatingJ semi-circular grooves 36,.d`eepest` ationy ofthe device.. rEhe inner:surface,ofthis ring has, opposite Y the yraised cams 130,/ coat their mddles. and tapering out, eachway. The normal diameter ofv the cylindrical clamping member, 'relative tov the. operating c [ring 34 is', suchV that when the partsjare as:-

sembledl and the, ring 34e is rotated to'such -pcsitionfthat the cams 3.0, aredirectly oppo- -fsite their respective camgrooves'36,.the. 011t-y er surfacesl of the curved sides; 265efithe clamping member are iny full. engagement with the inner surface, of-thering-3.4, as. shownv in Fig. 8, whilet'he cams() aretaken within the cam grooves. 36 as. shown, in` Figi.

7g. The parts areA so proportioned"tlmtiinthis.V

` position theY cylindrical clamp 25 passes.

VAloosely around the sides- 14a of the` upper leg secticn's,whi ch therefore donot bindkthe,

*flower leg section 2O` tightly b etvveenthem,

' andthe lower legsectionrmay be` slid;'freelyl l up or down for adjustment purposes.-

f Hin/ing` adjusted' the lower leg section, for length, however, thering 34 isJ grippedand;

rotated; whicl'n causes the cams and came Vgrooves Kto move relativelyto each other.and

thereby to force the cams linwardly relativer ly to the operating ring. Andfthis officoursm .causes the sidesz26 ofthe cylindrical' Clamp ing member 25 toA be-moved radially ,inward toward engagement withlr theV curvedi'outer surfaces of the 'leg seotionsla, the operatring. ringbeingrotat'ed tovv contract the cylindrical? clamping member until its sides 26,k

` are. tightly engaged withthe-upper leg sec-- tions 14, .when the lower'fleg Section, 2 0 vbe,-` comes tightly bound therebetween, I The.

partsgare'f then in the position,illustrated in Figs. 2', 3', andtit' bengncted; thatthere. is thenl a clearance between-.the wallsoffthe:

.curved sides "26. of` the clamping member, while the highest'points of the canlsfBO are-v practically removed from `thel cam grooves,- .I or arein .onlyvthe shallow end partsthereofY It will be noted from Figs. 3,;4',; 7 and 8.

, that the two sides 14a. of theupper leg sec.

tion are' shifted somewhat laterally-inopp'osite- Vdirections by.V the contracting move@ ment ofthe curvedsides 26 ofthe clamping the adjusted" position. y 'rotation requiredV ofthe'ring thus to clamp 1 or unclamp the legs may beninety degrees member. ,This movement is' provided for by giving the tongues 19 vclearance rvin the grooves 18, as clearly shown in the'drawings.

Thus to adjust the legsof thertripod for length, the ring is gripped and turned to f release theclamp`,' and then moved" to slide the lower leghseition upl or downto the desired position, after v vhiclik another lturnY of the ring-.tightly clampsuthe leg sections in And the amount of or less-,iso that a very simple movement serves quickly and easily to operate the clamp.

While 1I" V"larvenow illustrated and de-V scribed certainspecilic means,- for carrying olitfan embodiment; offlniyinvention-,it will. be obvious that` various changes. in, design, structure, and arrangementl 'may be4 eliected withoutdeparting from the spiritand scope. of my, invention; and` it is therefre'f tolbe understood that all. such changes are rcontemplated'withinthe. scope offmy, invention as, expressed. thevfollowing claims..V

f 1I. a device, .offtlei characterdescribed,4 the. combination. oft overlapping'k members, relatively longitudinallyslidable, said mem'-Y bers inassemblyhavinga cylindricalexternal surfa.ce a contractihlef member: surrounding said cylindricalA4 external surface, a; -ring` sur-- rounding sai'dicoiitractible v meunier,y and coef v operating camming elements between said ring and. lc ontractible membery 'adapted' by, virtueoj rotationofsaid ringtocontract saidA contractiblefrnember into. engagement with lili) member adapted by. virtneofroltationof said ring to contract? said contractible, member lionto, engagementlwith,said'overlapping memers.r v

3,-.. In adeviceof the. character described, the combination of .overlapping -members relativelylongitudinally slidable, said" inembers in assemblyhaving a .cylindrical eXter- L nal; surface,- a-longitudinally split'v cylindrical member surrounding said cylindrical external vsurface -andf comie'ctedwith one-ofsaid overlapping members, a ring surrounding said. split cylindrical .member, l and "cooperating camming elements between saidring and, said splitv cylindrical I nemberV adapted; by virtue ofi rotation. i off saidjkringto contract said" contrartible I'nemberl into. engagement v"tJIn a device of the'character described,

the combination of two spaced members over- 'lapping asingle member longitudinally slid,-`

able therebetween, said two spaced members `in assembly having .a cylindrical external 1 surface, a contractlble member surroundmg said cylindrical externalsurface, a ring surrounding said contractible memberyand cooperating camming elements between said ring and contractible member adapted by virtue of rotation of'said ring toy contract said contractible member into i engagement with said overlapping members. y y

5. In a device of the character'described, the combination of two spaced members overlappinga single member longitudinally slidable therebetween. said two spaced members yin assembly having va-vcylindrical external surface. a contractible member surroundlng said cylindrical externa-l surface and connected, with the overlapped end of said single memberso as to be longitudinally movable with said single member on said spaced members. a rino: surrounding. said -contractible member, and cooperating cammina'V elements between said ringy and Vcontractible member Vadapted bv virtue of rotation of said ring to contract said contractible member into en gagement with said overlapping members.

ing lcam groovegin the inner surface of said operating'ring.

8. In a device of the character described,

vthe combination of overlapping slidable members one within the other, a clamp member mounted on Vand carried by the inner member and having parts bearing on the exterior surface of the outer member, and means kday of May, V1930.

GEORGE A. MITCHELL.

6. In a device ofthe character described," the combination or' two spaced members over- .lapping a single member longitudinallv slid-` able therebetweenssaid two spaced members fin assemblv havin@ a cylindrical external surface. a contra ctible clamping member having a longitudinally split cylindrical part surrounding said cylindrical evternalsuryface and having-a part connected with the overlapped end of said sin EQ'le member. wberebv said clamping member is longitudinallv movable with said single member on said spaced members. a ring surrounding` said split cylindrical member` and` cooperating cammino elements between said rino' and said rsplit 'cvlindrical member adapted bv virtue of rrotation of said ring, toA contract said contractiblemember into engagement with saidy overlapping members.

7. In a device of the character described, tbe combination of two spaced members overlapping a single member longitudinally slid- 'able therebetween. saidy two spaced members kin assemblvhaving a cylindrical external surface, a contractible clamping member having a longitudinallv split cylindrical partV surrounding said cylindrical external surface and having apart connectedwith the overlapped end of said single member` whereby said clamping member is longitudinally movable with said single member on said spaced members. an operating ring surrounding said contractible cylindricallmem-ber. an outwardly extending cam on said splitcylindrical member, and there being a Ylimited cooperat- 

